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(No Model.) 2' Sheets-S heet '1 J. S. ,sTO-NE. DEVELOPMENT ANDDISTRIBUTION OF E-LBGTRIGITY. No. 487,102. Patented Nov, 29,1892.

W" ease Inraentor.

2 Sheets-Sheet 2.

(No Model.)

J. S'.STONE. DEVELOPMENT AND DISTRIBUTION OF ELEGTRIGITY. No. 487,102.Patented Nov. 29, 1892.

M M w T m 25 L2 [awn/607 UNITED STATES PATENT OFFICE.

JOHN S. STONE, OF BOSTON, MASSACHUSETTS, ASSIGN OR TO THE AMERICAN BELLTELEPHONE COMPANY, OF SAME PLACE.

DEVELOPMENTAND DISTRIBUTION OF ELECTRICITY.

SPECIFICATION forming part of Letters Patent No. 487,102, dated November29, 1892.

Application filed October 10 1891. Serial No. 408,330. (No model.)

To all whom it may concern:

Be it known that I, JOHN S. STONE, residing at Boston, in the county ofSuffolk and State of Massachusetts, have invented certain Im- 5provements in the Development and Distribution of Electricity, of whichthe following is a specification.

My invention comprises an improvement in the art of transforming,modifying, and controlling electric currents, an improvement in the artof electrically transmitting speech, and appropriate combinations ofappliances for carrying out the said improvements.

It consists in causing the operation of a r suitablecircuit-changer-such as a telegraphkey, a sparking-point, or avariable-resistance transmitter, according to the character of the Workto be accomplished-included in the circuit of a source of electricity tovary the potential of the charge of a condenser shunting the saidcircuit-changer and then in utilizing the variable alternating currentsdeveloped thereby in the inductive circuit of said condenser for theoperation of translating or 2 5 electro-receptive devices included insaid inductive circuit.

It further consists in combining with an electric circuit, including acircuit-changing or current-varying appliance and a fixed sim- 0 ple orinductive resistance, a shunt for the said appliance, which shuntincludes a condenser and directly or inductively a translating device.

It further consists in combining an electric 5 circuit, including atelephone-transmitter and a simple or inductive resistance, with a shuntfor the said transmitter, includinga condenser, and a telephone directlyor through the intermediation of an induction-coil in circuit therewith.

The invention also consists in the combination, with a single source ofelectricity, of a plurality of utilization-circuits, each including itsown circuit-changer or current-varyer 5 and its own condenser-shunt, andeach including conductively or inductively a receptive device-such, forexample, as a telegraph or telephone receiving-instrument or an electriclamp.

In the drawings which accompany and form a part of this specification,Figure 1 is a diagram showing one form of the arrangements of circuits Ihave devised as applied to telephony, a simple resistance beingassociated in the original circuit. Fig. 2 is a similar diagram in whichan inductive resistance is shown as being employed. Figs. 3 and 4 arediagrams illustrative of the applicability of my invention to apluralityof independent utilizing-circuits, including translating devices. Fig. 5indicates the operation of my invention in connection with atelegraph-circuit; and Fig. 6 is in substance the same as Fig. 1, withthe exception that the translating or receiving instrument is includeddirectly in the condensershunt, the interposed induction-coil beingdispensed with.

In Figs. 1 and 2, S is a suitable source of electricity, such as aprimary or secondary battery or a dynamo. M is a current-changer, (inthis instance a variable-resistance transmitter.) R in Fig. l and H inFig. Z'are resistances, in the first instance simple and in the latterinductive, and these instrumentalities are serially associated in anelectric circuit by the conductors 1, 2, 3, and 4. C is a condenserhaving one of its plates united by wire 5 to a point, as a, of thecircuit on one side of M and its opposing platesunited by wire 6 to apoint, as b, on the other side of M. The electro-receptive or utilizingdevice T (in this I instance a receiving-telephone) is connected withone of the condenser connections through the intermediation of aninductioncoil I, which has its secondary helix connected with the twoconductors Z and Z of the circuit L, leading to the said receptivedevice, and its primary helix in circuit with the condenser. In theoperation of this arrangement of circuits and appliances it is evidentthat the ourrent from the source S cannot circulate in the primary helixof the induction-coil, such current as does flou therein beingalternating and due to the variation of the charge of the condenser asthe difference of potential betweengg its terminals is varied by theoperation of the Variable-resistance transmitter. It is consequentlypossible to use a greater current than would otherwise be practicablewith the same size of primary wire and still obtain improved :00effects.

By employing a source of considerable electro-motive force and thenbringing the normal current to its proper value by means of suitableresistance R, I am enabled in the operation of the transmitter todevelopa greater variation of potential between the two sides of the condenserthan would be possible with the same normal current developed by a lowerelectro-motive force in a circuit where there is no other resistancethan the transmitter M. Good results, for example, may be obtained byemploying a source having an electro-motive force of one hundred volts,a resistance of, say, ninety-two ohms, and a transmitter having a normalresistance of eight ohms, or therealoout. The condenser may have acapacity of four microfarads. In circuits through which steady currentsonly flow there is, of course, little or no difference between theaction of simple and inductive resistances; but during the operationscontemplated by my invention the changes of current are in virtue of theoperation of the circuit-changer always relatively and in some casesabsolutely of high frequency, and the introduction of an inductiveresistancethat is to say, of a resistance constructed in a manner wellunderstood in such a way as to have a high coefficient ofselfinduction-acts to choke the current, so that by employing such aresistance as is shown at B Fig. 2, the same potential variations maywhen desirable be produced with a resistance which, measured in ohms, iscomparatively low, and consequently with a much lower originalelectro-motive force.

Fig. 6 is a modification of Figs. 1 and 2, in which the translatingdevice T is directly connected with the condenser connection, or, as itmay alternatively be stated, is included, together with the condenser,in an inductive circuit, which also includes the current-varying device,this latter element being in a branch common to the conductive andinductive circuits and the induction-coil I being dispensed with. Thischange can under certain circumstances be advantageously made, and tendstoward simplification.

In Figs. 3 and 4: the same source S is common to two or morecurrent-varying devices M. In Fig. 8 each of the cu rrent-changers M hasa circuit 1 2 3 4 and the resistance R or its equivalent. The condenserO in both cases is connected to shunt its own currentchanger M and isassociated with the induc-. tion-coil I, through which the circuitleading to the translating device is connected. The two sets ofconductive and inductive circuits in this instance are connected inparallelism with each other.

In Fig. 4 the independent current-varying devices M, M, and M are all inseries with one another and with the source S and the resistance R,while their respective inductive or dielectric circuits N, N, and Nconstitute condenser-including shunts, each of its own current-varyer.The inductive circuits N and N are both shown as operating theirrespective translating devices T and T inductively.

cuit conductively discontinuous, but having associated a condenser orequivalent appliance through whose agency either terminal of the circuitmay on any change of its electrical condition inductively act upon theother and produce by such action a variation of its charge andconsequent movement of electricity in the remaining portions of thecircuit, and by the term conductive circuit is meant an electric circuitwhich is continuously conductive throughout in such a way that a voltaiccell included therein will of itself develop a continuous current,"whichwill circulate until the said cell is exhausted or the circuit at somepoint broken. Thus in Fig. 1 the conductive circuit, beginning at theplus pole of battery S, may be traced through conductor 4, point a,variable resistance M, conductor 3, pointb, conductor 2, fixedresistance R, and conductor Z to the minus pole of the battery, While inthe same system the inductive circuit is traceable from point a, throughconductor 5, condenser C, conductor 6, induction-coil helix 19, pointI), conductor 3, and variable resistance M back to a, the condenserconstituting an inductive but non-conductive connection between thesevered ends of the circuit, and the section included between a and I)through the variable resistance being common to both circuits. In thesame Way, referring to Fig. 6, the conductive circuit leads from onepole of the battery through the fixed resistance R and variableresistance M back to the other pole of said battery, while the inductivecircuit extends from one plate of the condenser through the conductorsL, the distant telephone T, and by Way of the variable resistance M tothe other condenser-plate.

Fig. 5 is illustrative of the application of this invention totelegraphy. The source S (shown as a dynamo) is connected up in acircuit X with the resistance R and key M. The condenser O, as before,is included in an inductive circuit of which the current-changer Mlikewise forms a part, and a loop extends from the condenser connectionsto the electro-receptive devicein the present instance a polarizedtelegraphic receiving-instrument.

It will thus be seen that my invention has a wide applicability; and,

Having fully described the same, I claim- 1. The combination of aconductive circuit, an inductive circuit, and a single-bridge connectionforming aconductive section common to both of said circuits with anelectrical generator in the said-conductive circuit, a translatingdevice in the said inductive circuit, and a current-varying deviceincluded in the said bridge connection, substantially as described.

2. The combination, substantially as hereinbefore described, in anelectrical developing and distributing system, of a source ofelectricity, a current-varying device, and a suitable resistanceassociated in a conductive electric circuit with a condenser connectedup in an inductive electric circuit comprising that portion of theconductive circuit which includes the said current-varying device and anelectro-receptive or translating device included directly or inductivelyin said inductive circuit.

3. The combination, in a system of telephonic transmission, of avariable-resistance transmitter, a source of electricity, and a suitableresistance associated in an electric circuit with a condenser connectedin a shunt of the said circuit round the said transmitter and areceiving-telephone connected directly or inductively with the saidcondenser-shunt, substantially as described.

4. The combination, substantially as hereinbefore described, in a systemof telephonic transmission, of a variable-resistance transmitter, asource of electricity, and a suitable resistance associated in anelectric circuit with a condenserconnected in a shunt of the saidcircuit round the said transmitter and an induction-coil havingitsprimary helix included in the condenser-shunt and its secondary helix inmain telephone-circuit.

5. In a system of telephonic transmission, a variable-resistancetransmitter, a source of electricity, and an inductive resistanceassociated in a local electric circuit, combined with an electrostaticshunt for the said transmitter,which shunt contains a condenser and isconnected with a main telephone-circuit in cluding areceiving-instrument.

6. In a system of telephonic transmission, a series of independentcurrent-varying transmitters, each shunted by a condenser, and a workingcircuit associated therewith, including a receiving -telephoneelectrically connected with the said condenser-shunt and adapted to beenergized by the currents circulating therein, combined with a source ofelectricity connected with and common to the said series of transmittersand a suitable re sistance to determine the normal current flowingthrough the transmitters, substantially as shown and described.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 6th day of 0ctober, 1891.

J. S. STONE.

Witnesses:

GEO. WILLIS PIERCE, J OSEP A. GATELY.

